The friendly merger would reinforce Masmovil's position as the fourth-largest operator in Spain's crowded telecoms sector.
The non-binding recommendation comes after the Spanish government approved the deal last month.
Euskaltel's major shareholders Zegona, Kutxabank and Corporacion Financiera Alba - which together own 52.32% of Euskaltel - agreed in March to accept the offer of 11.17 euros per share in cash, a 16.48% premium at the time.
($1 = 0.8422 euros)
(Reporting by Emma Pinedo; Editing by Nathan Allen)